Beluga Whales Have Adopted a Lone Narwhal, May Make Hybrid 'Narluga' Babies

Researchers are poised to see whether a lost narwhal that was adopted by a pod of beluga whales a few years ago will mate with its companions to produce a hybrid animal.

The unusual group of cetaceans was first spotted in St. Lawrence River in North America in 2016. The lone male narwhal appeared to have been adopted by a pod of belugas and has been traveling with them ever since, as if he were one of their own.

The case has bemused scientists. Both Narwhals are beluga whales are found in the Arctic ocean, belugas tend to migrate further south in the winter, as sea ice forms. Narwhals do not tend to leave the Arctic, spending up to five months under sea ice.

Narwhals have been known to stray away from the Arctic occasionally, however this case is extremely rare.

Over the years, scientists have used drones to assess the narwhal's growth, CBC reported. They know from markings on its body that it is the same male, narwhal spotted every time. It is also healthy, and well-integrated into the group. However, this is still a lot they do not know.

While adoption among species can be explained for a variety of reasons, subspecies adoption still baffles scientists. In a 2018 article, behavioral ecologist Erin Siracusa said that it might be for protection against predators, for a "safety in numbers" benefit. Another explanation could be that both species are social creatures, and the adoption took place for companionship. This, however, is unlikely to be the sole reason for the peculiar friendship, Siracusa said.

Researchers estimate the male narwhal is now about 12 years old and reaching sexual maturity. Robert Michaud, president and scientific director of the Group for Research and Education on Marine Mammals (GREMM), told The Current that "hybridization is possible" and has happened a few times, meaning a "narluga"–a cross between the two animals–may be on the cards.

Michaud said the high level of integration of the narwhal into the group means breeding is a possibility. There have also been lots of social interactions between the narwhal and the beluga whales, including the usual "social-sexual behaviors in both directions."

"He is one of the crew; he is one of the buddies in there," Michaud said. He told The Current that researchers will continue to monitor the narwhal, and begin to look for any offspring.

To reproduce, the young narwhal will have to get close enough with the other males in the pod to join a coalition, Michaud said. If the young male manages this, the narluga calf would have to grow in order for scientists to distinguish it from normal beluga calves.

There have been documents of "narluga" before. In 2019, the University of Copenhagen assessed the DNA of an unusual skull found in Greenland in 1990. The researchers found that it belonged to a first-generation hybrid between the two species. It is however unclear whether this hybrid was able to reproduce itself.